Apologist Ravi Zacharias had admitted he "failed to exercise wise caution and to protect myself from even the appearance of impropriety" when addressing a personal lawsuit involving a married woman who sent him nude photos.

On Sunday, Zacharias and his organization, Ravi Zacharias International Ministries (RZIM), released a statement one month after settling a lawsuit with a Canadian couple Zacharias claimed had attempted to extort him over messages he had exchanged with the wife.

"I have learned a difficult and painful lesson through this ordeal," the 71-year-old speaker and author said. "I failed to exercise wise caution and to protect myself from even the appearance of impropriety, and for that I am profoundly sorry. I have acknowledged this to my Lord, my wife, my children, our ministry board, and my colleagues."

Christianity Today reports that the lawsuit, filed by Zacharias, alleges that he met the couple at a speaking event in Canada in 2016. However, his "friendly correspondence" with the wife resulted in her sending him "unwanted, offensive, sexually explicit language and photographs." Zacharias said the wife continued to inappropriately communicate with him, even after he asked her to stop and blocked her messages. 

The woman eventually "began expressing her love for [Zacharias], and then began making sexually suggestive statements," according to the lawsuit, and sent him photos of herself in "very scanty clothing," and finally, of herself nude. 

In April 2017, the couple sent a letter through their attorney demanding millions of dollars in exchange for keeping the messages a secret.

Zacharias subsequently sought legal advice and launched a legal suit, which was later settled through mediation rather than going to trial. The case was dropped last month when an agreement was made and both sides agreed to confidentiality.

"Let me state categorically that I never met this woman alone, publicly or privately," Zacharias said in his statement. "The question is not whether I solicited or sent any illicit photos or messages to another woman - I did not, and there is no evidence to the contrary - but rather, whether I should have been a willing participant in any extended communication with a woman not my wife. The answer, I can unequivocally say, is no, and I fully accept responsibility. In all my correspondence with thousands of people in 45 years of ministry, I have never been confronted with a situation such as this, and God and my family and close friends know how grieved I have been."

Zacharias said he bore "no ill will toward anybody' and insisted he "never engaged in any inappropriate behavior of any kind."

"Iexercised extreme caution in my daily life and travels, as everyone who knows me is aware," he contended.

"I have long made it my practice not to be alone with a woman other than Margie and our daughters - not in a car, a restaurant, or anywhere else. Upon reflection, I now realize that the physical safeguards I have long practiced to protect my integrity should have extended to include digital communications safeguards. I believe - and indeed would counsel others - that the standards of personal conduct are necessarily higher for Christian leaders."

In a separate statement from RZIM on Sunday, the organization also addressed claims Zacharias has been lying about his credentials and falsely implied that he had earned a doctoral degree despite only having honorary degrees.

"Neither Ravi nor his ministry has ever claimed he had an earned doctorate," the statement said, adding that "in earlier years, 'Dr.' did appear before Ravi's name in some of our materials, including on our website, which is an appropriate and acceptable practice with honorary doctorates.'

"However, because this practice can be contentious in certain circles, we no longer use it," it continued. " We will be more vigilant about editing and fact-checking at every stage."

It concluded: "Ravi's desire and our desire as an evangelistic ministry is to engage the honest skeptic, to take questions seriously, and to be as clear as possible in our communication. We therefore have restructured Ravi's biography to better reflect his 45 years as an itinerant evangelist and apologist with a passion and a calling to reach those who shape the ideas of culture with the beauty and credibility of the gospel."